Method of making wrought iron



I. ASTON.

METHOD OF MAKING WROUGHT IRON.

APPLICATION FILED APR. 24. 1920.

Patented A an-18, 1922.

50 rolled into skelp, or other semi-finished or JAMES ASTON,

PANY, OF PITTSBURGH, PENNSYLVANI or rrrrsBuNei-r, rENNszLvANIA, AssreNoa ro A. N. BYERS coir- A, A CORPORATION OF PENNSYLVANIA.

- IlEETI-IOD F iii/TAKING WROUGHT IRON.-

To all whom it may concern Be it known that I, JAMEs As'roN, residing at Pittsburgh, Allegheny County, Pennsylvania, have invented a new and useful Improvement in i the Methods of Making Wrought Iron, of which the following is a full, clear, and exact description, reference being had to the accompanying drawing, forming part of this specification, in whichv The figure is a diagrammatic view showing one form of apparatus for carrying out my invention.

In my application, Serial No. 337,995, filed November'14, 1919, for method of making wrought iron, I have described a method, in the preferred form of which the product of a steel-making process is granulated or comminuted and then mixed with slag, preferably by dropping the granules into a slag bath, -where a coherent mass or ball is formed.

' I have found a simpler, cheaper and easier way of granulating and making a coherent mass orball, which consists in pouringthe molten product of the steel-making process directly into the bath of slag of the proper characteristics. I have found that when a stream of steel is poured into a bath of molten slag, it will become granulated, the granules dropping through the bath and cohering to form a mass or ball conforming generally to the bottom portion container, such as a slag ladle. It is there fore unnecessary under this invention to granulate or comminute the steel in the air before it reaches the slag bath, since the metal will be granulated by the molten stream entering the slag bath. The granules take the form of a sort of sponge, which is thoroughly intermingled with the slag, giving a mass or ball of these particles which weld together and form a ball ready for compressing.

surface of the slag bath which protects the metal from the air, and by making a suffi 'ciently large ball or mass, I can roll the same after compressing directly into slabs or billets without repiling. These slabs or billets may then be rolled, reheated and finished product.

for making molten steel.

of the slag.

This is formed below the Specification of Letters Patent. Pwbgntgd A 1% 1922 Application filed. April 24, 1920. Serial No. 376,247.

In the drawing, in which I show diagrammatically one form. of apparatus'for carrying out my invention, 2 represents a slag heating furnace in which a puddling slag may be prepared. These slags'are essentially iron silicates containing ferric oxide,

ferrous oxide, silica, phosphoric oxide and erably employ carbon on or in the slag bath which may be in the form of crushed coke, carbon electrodes, etc, to keep the percentage of ferric oxide low and to reduce the-same tosome extent. Thecoke or other carbon blanket over the slag will, of course, be held back when the slag is poured into the ladle 3 from this slag-heating furnace. The ladle 3 may be mounted on a truck 4, by which it may be carried under a pouring stand, indicated at 5. The product of the steelmaking operation may be taken from a steelmaking furnace, consisting of a Bessemer converter, an open-hearth furnace, an electric furnace, or anyother desired apparatus A suitable charge for a large ball, say 2,000 pounds, is tapped out of this furnace into a ladle 7, which. ladle may then be taken by an overhead crane to the pouring stand directly above the ladle of slag. The height is preferably about eight feet for the drop of the stream ofmetal. This, however, may be varied within wide li'mits in both directions, and the desired result obtained. The

" steel ladle is'preferably a bottom-pour ladle.

The molten metal may be poured directly from the steel-making furnace without the use of a ladle," in which case, the necessary height of fall may be obtained by elevating the steel-making furnace or mounting it above thepouring station.

When the stream of steel drops into the slag bath, it becomes granulated as it strikes and passes through the slag batlrand forms a ball or coherent mass of welded particles,

thoroughly intermingled with the slag This mass takes the general shape of the bottom of the slag ladle anclliesunder the surface of the slag, of which there is a sur- -plus over the amount necessary for intermingling with the metal in forming the ball.

After this operation, the surplus slag may be poured out by tipping the ladle, the slag preferably passing through a screen 8, intoaj slag bucket or ladle 9, in the pit underneath the same. Instead of feeding the surplus slag into the slag receptacle by which it may be returned to the furnace, the surplus slag may be poured directly back into the slagmelting furnace. The coherent ball of wrought iron is then taken out of the ladle to a squeezing apparatus 10, which is shown as of the press form, although it may be of the rotary squeezer type or any other desired t e. The ress form is desirable, Y]? P as the metal may thus be compressed into the desired shape, without turning-or manipulating.

From the squeezing apparatus, the large ball is taken to a blooming at the same heat into slabs or billets. Or the bloom may be taken to a soaking pit for holding and equalizing its heat or for being further heated prior to rolling it into slabs or billets. These slabs orv billets'may then b'e stored andpassed through a continuous heating-furnace to a skelpmill where they I slag and the metal, the granulated iron will solidify inthe spongy mass or ball, on-account of its being at the weldingheat necessary for that purpose. slag may vary and -.the temperature of the ball may vary to a considerable extent, as it .is taken out of the 'ladle or slag receptacle.

The ball maybe subjected to a soaking pit operation to equalize the temperature through this mass after squeezing.

Theexcess slag from the. ball which is poured through the grating into the excess slag receptacle may be returned totheslagheating furnace. v If this is. done, however, l have discovered that the slag should be re- 'vivified by the addition of silica. The form- I ing of the ball [introduces some. iron oxide into the slag, thereby diluting the iron sili-- 'cates so that to keep the slag of the proper physical. and chemical characteristics, the

slag'which isvreturned to the bath should be revivified by the-addition of silica.

The formation of ferric oxide in the slag may be retarded or prevented by keeping a blooming mill.

mill and rolled The heat of the reducing atmosphere instead of an oxidizing atmosphere in the slag-melting furnace.

The slag receptacle may consist of a large ingot mold and after the large ball or mass is formed and the excess. slag removed, the mass may be compressed or squeezed in this mold and then taken to a soaking pit where the heat is equalized through the mass, the compressed mass being then taken to the Such a process is described in'my copending application Serial No. 376.388, filed April 24, 1920.

The steel, which I employ is preferably a. low carbon steel, though the percentages of metalloids in the steel may be varied widely without departing from my broad invention. Many changesmay be made in' the ap-- my process, without departing from my i-nvention. Within the scope of my claims, parts of my complete process forming subprocesses, may be used, without departing from my invention.

Ielaim: T

1. The method of producing wrought iron, consisting in pouring the molten substan tially' slagless product of a steel-making process intoa slag bath, thereby-comminuting the metal in the bath, and forming the mixture into a coherent mass, substantially as described. a

2. The method of producing wrought iron, consisting in pouring the molten "substan- 1 tially slagless product of a steel-making process into a. bath of 'puddling slag having the proper physical and chemical characteristics, thereby comminuting the metal in the paratus employed, as well as in the steps of bath, and forming a coherent mass of mixed slag and metal below thesurface of the slag I in the bath, substantially as described.

3. The method of producing wrought iron, a consisting in pouring the molten substanbath, and forming a coherent partially,

shaped mass of slag-and metal underneath the surface of the slag and corresponding to the shape of the lower part of the slag receptacle, substantially as described.

4c. In the method of vproducing wrought iron, the steps consisting in providing a bath of an iron silicate slag of proper physical andch'emical characteristics, pouring the molten product of the steel-making process into said bath, thereby comminuting the metal in the bath, and forming a. coherent mass of mixed metal and slag therein, sub stantially as described.

. '5.In the method of producing wrought iron, the steps consisting of feeding the molten products of a steel-making process into a bath of slag of the proper physical iron, the steps consisting of pouring and chemical characteristicsfor' making wrought iron, comminuting the steel after it strikes the slag bath, and causing the metal granules to contact with each other below thesurface of the slag bath while at welding temperature, thereby forminga coherent mass or sponge beneath the surface of the slag bath, substantially as described.

6. The method of producing wrought iron, consisting in pouring the molten substantially slagless product of a steel-making process into a slag bath, thereby comminuting the metal in the'b'ath, iormihg. the mixture into a coherent mass, "freeing the mass from the surplus slag, and compressing it, substantially as described.

7. In the method of producing wrought a'stream of the molten product of. a steel-making process into a bath of slag oil the proper characteristics, forming a spongy shaped mass of mixed steel and iron in the bottom portion of the slag receptacle, removing the mass from the receptacle, and compressing it, substantially as described.

8. In the method of producing wrought iron, the steps consisting of maintaining a molten bath of iron silicate slag of the proper characteristics for making wrought of ferric oxide therein, feeding successive portions of the slag into receptacles, feeding the molten product of asteel-making process into the slag inthe receptacle, and form- 'ing a spongy mass of slag and metal therein,

substantially as described.

9. In the method of producing'wrought iron, the steps consisting of maintaining a molten bath of iron silicate slag of the proper characteristics, preventing or. retarding the formation of r'errlc oxide in the bath, feeding out a portion of the bath into the slag receptacle, pouring the molten product of a steel-making process into the slag in the receptacle, thereby comminuting the same and forming a wrought iron sponge in the bottom of-thereceptacle, and then removing and compressing the same, substantially as described.

10. In the method of producing'wrought iron, the steps consisting ofpouring the molten product of a steel-making process into a receptacle containing ab-ath of slag of 'the. proper characteristics to make wrought iron, forming a large wrought iron ball or mass therein, squeezing or pressing the same, and rolling it directly into slab or billet form, substantially as described.

11. In the method of producing wrought the steps consisting of pouring the iron, Y molten product of a steel-making process into a receptacle containing a bath of slag of the proper characteristics to make wrought iron, forming a large wrought iron ball or mass therein, squeezlng or pressing iron, preventing or retarding the formation by mixing the molten product of or ball of wroughtkiron,

into a receptacle containing a bath of slag.

of the proper characteristics to make wrought iron, forming therein a large mass or puddle ball of such a size as not to require repiling, and rolling the same directly into the desired product, substantially as described.

13. In the method of producing wrought iron, the molten product of a steel-making process into a receptacle containing a bath of slag of the proper characteristics to make Wrought iron, forming therein a large mass or puddle ball of such a. size as not to require repiling, and squeezing and rolling the same directly into the desired product, substantially as described.

14. In the process of makingv wrought iron by mixing the molten product of a steel-making process with slag of the proper characteristics for making wrought iron, the step consisting of removing the surplus slag from the ball or mass, and revivifying the slag, substantially as described.

15 In the process of making wrought iron a steelmaking process with slag of the proper characteristics for making wrought iron, the step consisting of removing the surplus slag from the ball or mass, and revivifying the slag by adding silica, substantially as de scribed.

16. In the method of producing wrought the steps consisting of maintaining a molten bath of slag of the proper characteristics for making wrought iron, withdrawing a portion thereof into a slag receptacle, feeding thereinto the molten product of a steel-making process to form a spongy mass freeing the mass iron,

steps consisting of pouring the from the surplus slag, and revivifying and returning said slag to the general bath of molten slag, substantially as described,

17. As a new article of manufacture, a shaped spongy mass of wrought iron formed of the granulated product of a steel-making process mixed with slag of wrought iron characteristics, substantially as described.

18. A spongy mass of wrought iron formed of the granulated product of a steel making processmixed with slag of wrought iron characteristics, said mass having the shape of the receptacle in which themixture is formed, substantially as described.

19. A. spongy mass of wrought iron formed of the granulated product of a steel making process mixed with slag of wrought iron characteristics, said mass having the shape of thereceptacle in which the mixture too 4L I emma 7 is formed and being of less density than wrought iron characteristics, said mass be that of hand p-uddled balls, substantially as ing ofsufiicient size to be rolled'direct into described. n slabs or billets without'cutting and repiling, 10

20. As a, new article of manufacture, a substantially as described." 4

5 shaped, and compressed mass of wrought In testimony" whereof, .I have hereunto iron formed of the granulated product of a, set my hand. v steel-making process mixed with slag 01E i J JAMES ASTON. 

